Comparison of Thermal Stability and Chemical Bonding Configurations of Plasma Oxynitrided Hf and Zr Thin Films
Journal of the Electrochemical Society
In this work, we study the characteristics of plasma oxynitrided Hf and Zr thin films. A 5-nm-thick Hf or Zr metal film is deposited on the bare Si substrate, followed by plasma oxynitridation on these metal films in a N 2 O or NH 3 ambient. Incorporation of O and N leads to the formation of HfO x N y and ZrO x N y films. The high nitrogen content in the HfO x N y films prepared by NH 3 plasma oxynitridation is found to increase the onset of the crystallization temperature, as compared to films
... s compared to films prepared by N 2 O plasma oxynitridation. Nevertheless, the difference in crystallization temperature is not seen for ZrO x N y films. The interlayer ͑IL͒ between HfO x N y ͑or ZrO x N y ͒ and Si is found to be thinner for the films with NH 3 plasma oxynitridation than those with N 2 O plasma oxynitridation. However, the nitrogen incorporated by plasma oxynitridation appears to be depleted after rapid thermal oxidation annealing and is not effective to inhibit the growth of the IL. The activation energy of the IL growth for N 2 O and NH 3 oxynitrided HfO x N y is 0.23 and 0.13 eV, respectively. The activation energy of the IL growth for N 2 O and NH 3 oxynitrided ZrO x N y is 0.19 and 0.14 eV, respectively.